This invention relates to vacuum cleaning machines. In particular, the invention relates to a self-contained, portable hydro-vacuum cleaning machine which is configured for quiet operation and which performs all of the following cleaning applications: wet vacuuming, hydro-extraction vacuuming (combined spray cleaning and wet vacuum), and pressure washing. Both the vacuum operation and the pressure operation are dual mode operations.
As used here, "dry vacuuming" involves the application of vacuum suction by an applicator tool to lift dirt and debris from a surface for transfer through a vacuum hose to a temporary storage container. "Wet vacuuming" also involves the use of vacuum pick-up, but in a system which has sufficient suction lift capability and water-tight construction to lift and transfer liquid and debris, typically to a sewer drain or a temporary storage tank. "Hydro-extraction" vacuuming or "steam" cleaning involves the application of a high pressure stream or jet of an aqueous emulsifying solution to a surface and simultaneously or subsequently applying a wet vacuuming operation to pick up and transfer used cleaning solution to a temporary storage tank. State-of-the-art machines mount the cleaning liquid nozzle and the vacuum pick-up head in the same applicator tool to facilitate the hydro-extraction operation. "Pressure washing" typically involves the application of the high pressure cleaning solutions or water to a "gun like" applicator tool having a nozzle and a trigger to activate the high pressure jet of water for cleaning surfaces or machines of grease and foreign matter. As used here, "vacuum unit" refers to the combination of motor and fan/impeller which is used to generate vacuum suction. Also, "vacuum motor" and "vacuum blower" refer to a vacuum unit.
There are available very few portable and self-contained machines which are adapted for multiple functions alone or in combination with dual vacuum operation using series and parallel connection of two or more vacuum motors. Typically, conventional self-contained or portable systems are limited to single function, wet or dry operation, or to dual function capability. This limitation exists because different functions require separate equipment systems which impose prohibitive space and complexity requirements on such units and, particularly in the case of portable units, excessive weight. The space, weight and complexity constraints are even more difficult in high pressure, liquid cleaning operations or high vacuum suction operations or, in particular, in
The only built-in self-contained systems known to me which have hydro-extraction and multiple function capabilities are the ACS Model 831 System and the ACS Model 431 System which are available from the Automated Cleaning Systems Division of Rug Doctor, Inc., Fresno, Calif. The ACS Model 431 System is shown in FIG. 1 and is designated by the reference numeral 9, whereas the ACS Model 831 System is shown in FIG. 2 and is designated by the reference numeral 10. The self-contained system 10 includes a central vacuum and pump unit 11, a separate chemical container unit 12 and a separate interceptor filter 13. The totally self-contained system 9 has a chemical container unit and filters which are integrated into the central unit.
Referring further to FIGS. 1 and 2, both the Model 431 System 9 and the Model 831 System 10 use a vacuum/high pressure/electrical conduit system such such 14 which connects the central unit 9 or 10 to individual wall-type outlets 15. Various types of applicator tools 16 can be releasably connected to the outlets 15 via a flexible hose, generally designated 17, for performing various cleaning functions. Despite the relatively small size of the systems 9 and 10--the central unit 11 of 10 is only about 31 inches deep.times.55 inches wide.times.48 inches high, whereas the dual vacuum version of system 9 is about 18 inches deep.times.21 inches wide.times.52 inches high--these systems are designed to accept different applicator tools 16 and to perform a number of different cleaning functions. These include all of the following functions: (1) central dry vacuum cleaning and dry vacuum extraction (at one or more machine wall outlets 15 simultaneously); (2) wet cleaning and drying (of air conditioning filters, refrigerators, kitchens, etc.); (3) wet cleaning of upholstery, etc.; (4) wet cleaning and instant drying of hard surfaces such as vinyl, concrete or tile floors; (5) hydro-extraction carpet cleaning and (6) hot/cold pressure washing and degreasing.
To implement these functions, central unit 11 of the Model 831 System 10, FIG. 2, contains on-board vacuum suction systems and liquid pumping systems; an automatic metering system for mixing selected concentrated chemical solutions with water; a chemical solution holding tank for temporarily storing the water-chemical mixture prior to application by the high pressure pumping system; and a waste recovery tank. The separate chemical container unit 12 holds a number of containers of concentrated cleaning/treatment solutions which are selected at wall outlets and metered at the central unit 11 for delivery to the on-board holding tank and, then, to the applicator tool 16. The system 10 uses a duplex pump which provides standard pressure of about 350 psi for hydro-vacuum extraction cleaning and 700 psi for pressure washing. A positive displacement vacuum unit provides 215 cfm (cubic feet/min) of air at 180 inches of water lift (in. Hg).
The totally self-contained Model 431 System 9, FIG. 1, contains, on-board, a vacuum suction system, a liquid pumping system, an automatic metering system and a chemical solution holding tank, as does the machine 10, and also a chemical container unit and a wall-type outlet. The machine 9 also includes a modular liquid pumping system which can be readily replaced by a system of different capacity, that is, by a pumping system which provides different pressure ratings and flow rates.
Furthermore, the system 9 is configured to use two or more vacuum units which are connected in series, in parallel or in series-parallel to provide optimized vacuum suction and air flow at the applicator tool 16. The basic vacuum system includes a single horizontal row of two vacuum units. Alternatively, one or more supplemental frame sections, each of which mounts two additional vacuum units, can be mounted in piggy-back fashion on the existing vacuum frame section.
Example of parallel, series and combined series-parallel connections for the Model 831 System 9 are shown respectively in FIGS. 3, 4 and 5 for a four vacuum unit system. The figures schematically illustrate the particular vacuum unit connections to one another and to waste recovery tank 19. For purposes of illustration, it is assumed that each vacuum unit 18 provides air flow of 90 cfm, and 95 inches of water lift (sealed). A parallel connection such as that shown in FIG. 3 maximizes air flow. For the stated vacuum unit capacities, the four-blower parallel arrangement provides 170 cfm air flow and 95 inches of water lift. For buildings which require long vacuum pipe runs, or simply to maximize vacuum suction at somewhat reduced air flow volume, a series connection such as that shown in FIG. 4 can be used. For the stated vacuum unit capacities, the series arrangement of FIG. 4 provides 90 cfm air flow and 180 inches of water lift. Finally, a series-parallel arrangement provides an optimized combination of air flow and water lift/suction. For the stated capacities, the series-parallel arrangement of FIG. 5 provides air flow of about 130 cfm and approximately 160 inches of water lift.
A portable hydro-extraction cleaning machine which is commercially available from Rug Doctor, Inc. of Fresno, Calif. is shown in FIG. 6 and identified by the reference numeral 20. This system 20, which is commercially designated R-150, includes a tank or base 21 which incorporates a chemical solution holding tank, a waste recovery tank and the associated pumps and fittings for providing hydro-extraction operation. Handle 22 is mounted to the base for pushing/pulling the machine 20 on wheels 23 and 24. The drawing also illustrates the location of the vacuum hose connection 25, pressure line connection 26 and a manual dump valve handle 27 which is used to effect manual dumping of the contents of the waste recovery tank.
While the system 20 is not configured to provide dry vacuuming or pressure washing, otherwise the general principles of operation are similar to those of the System 9, FIG. 1, and the System 10, FIG. 2. However, the machine 20 is adapted to use a single vacuum unit or a pair of vertically stacked units which are mounted within the chamber defined in the vacuum exhaust head 28. The optional dual vacuum unit system can be configured in series or in parallel. By way of example, a selectable series/parallel vacuum system for the machine 20 is shown schematically in FIG. 7. The inlet to the fan of the lower unit 29 is indicated at 30, while the outlet pipe 31 thereof is connected to a three-way valve 33 which selectively connects the lower unit 29 (1) to exhaust pipe 34 or (2) to the inlet pipe 32 for the upper unit 29. The upper unit is connected to exhaust pipe 35, which is also shown in FIG. 6. Connections (1) and (2), respectively, provide parallel and series operation of the two vacuum units 29-29.
Referring to FIG. 6, vents or openings 36 are provided on opposite sides of the vacuum chamber of system 20 (only one vent is shown in FIG. 6) to provide a cross-flow of cooling air for the vacuum units within the chamber. For two, 2-horsepower vacuum unit motors, each of which provides about 90 cfm air flow and 120 inches of water lift, series operation provides about 170 inches of water lift and 90 cfm air flow, while parallel operation provides about 109 inches of water lift and 180 cfm air flow.
As suggested by the above description, the machine 20 is versatile and commercially successful, as are the machines 9 and 10. However, like other vacuum systems, quieter operation is desirable, yet can be difficult to achieve. In particular, the exhaust sound level increases considerably when a plurality or multiplicity of vacuum blowers are used. The noise, of course, is particularly loud in the vicinity of the discharge opening of the exhaust pipes which are used in such machines.
FIG. 13 schematically discloses a conventional horn-shaped exhaust system 28 which may benefit from reduced exhaust noise level. In the horizontal sectional view shown in FIG. 8, the vacuum system 28 contains a motor 38 which is exhausted via a generally horn-shaped pipe system 39 of increasing cross-section along the direction from the motor 38 to the outlet in the side of the system 28.